We synthesized protein-coated gold nanoparticles using green and chemical reduction routes for cellular uptake study. In the current work, we coated gold-aryl nanoparticles of the type AuNPs-C6H4-4-COOH with BSA, collagen, zein and lysozyme proteins. Both routes were carried out without phase-transfer catalysts or extraneous stabilizing agents. High crystallinity of the AuNPs synthesized by the green route can be seen in the transmission electron microscopy images. Osteosarcoma cancer cells are malignant bone tumors with abnormal cellular functions. Studies using MG-63 cells will provide mechanistic suggestions on the details of the amplification in tumors. We studied the cellular uptake of the bioconjugates by MG-63 osteosarcoma cells using laser confocal fluorescence microscopy (LCFM) and flow cytometry. In the LCFM study, BSA-AuNPs was uptaken most efficiently of all protein-coated gold nanoparticles synthesized by the green route. Zein and lysozyme coated nanoparticles, though small sizes, prepared by the green method were not efficiently uptaken by MG-63. The two nanoparticles are negatively charged and zein is also a hydrophobic coat. The difference in hydrophobicity and charge might have affected the internalization. All of those coated nanoparticles that were efficiently uptaken can potentially be used as diagnostic and therapeutic agents for osteosarcoma.
This is the first version to be submitted to Langmuir, ACS.